These look like key areas to me….
https://www.fiercewireless.com/wireless/at-t-looks-to-sell-600-mhz-spectrum-to-lb-license-co-for-nearly-1b
“ The nation’s No. 2 mobile network operator filed a document with the FCC indicating it would transfer its 600 MHz holdings to LB License Company, an affiliate of Columbia Capital, a Beltway-area venture firm focused on telecom and media. While the filing doesn’t disclose terms of the deal, the website Facticia earlier this week reported LB Spectrum Holdings planned to raise $928 million. AT&T's full FCC filing is available at the bottom of this article.”